System for designing and rendering personalities for autonomous synthetic characters

ABSTRACT

Personality traits displayed on a workbench are grouped into a character profile that is utilized in determining the personality and/or specific actions of a synthetic character. The personality traits are selectable by an operator from graduated dials. The personality traits may also be displayed in the form of selectable attributes or trait indicative behaviors that, when selected, are mapped into predetermined amounts of each trait in the character profile. The character profile is utilized to compute activation levels for primary behaviors, which are selected to influence or direct behavior of the synthetic character. Secondary behaviors are also selected, but discarded if conflicting with the selected primary behaviors. When behaviors are selected, the corresponding behaviors are translated into classes of ‘personality effectors’ that modulate the synthetic character&#39;s behavioral expression to reflect the desired set of traits.

COPYRIGHT NOTICE

[0001] A portion of the disclosure of this patent document containsmaterial which is subject to copyright protection. The copyright ownerhas no objection to the facsimile reproduction by anyone of the patentdocument or the patent disclosure, as it appears in the Patent andTrademark Office patent file or records, but otherwise reserves allcopyright rights whatsoever.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates to human-computer interfaces (HCI). Theinvention is more particularly related to a tool set for modeling andcreation of a personality for an animated anthropomorphic character HCIthat interacts with a user. The invention is even more particularlyrelated to a tool set that allows the inclusion of new and themodification of existing personality attributes to produce a unique andengaging anthropomorphic character personality.

[0004] 2. Discussion of the Background

[0005] Autonomous synthetic computer characters have become atechnological and commercial reality in the last few years, both asalternative user interface mechanisms and as entertainment devices. TheMicrosoft Office Assistant, Microsoft Agent, IBM's Warp Guide, andExtempo's Imp Software are all recent attempts to commercialize userinterface technology developed over the last decade at academic researchinstitutions. The explosion in computer games which utilize syntheticcharacters and their increased use in television and motion picturesalso indicate a strong demand for advances in this technology.

[0006] One such advance is the basic action selection architecture(BASA) developed in the ALIVE project at the MIT Media Lab. The BASA isused for run-time simulation of characters in deliverable applications.

[0007] In the BASA, behaviors are arranged in a hierarchy with those atthe top of the hierarchy being more abstract categories of behavior andthose at the bottom being operational in that they have simulationroutines associated with them which allow the character to perform themwhen commanded. Behaviors at each level in the hierarchy compete everytime step of the simulation for control of the character. The result ofthis competition is one primary behavior, which is the primary actionthe character performs at that time step.

[0008] However, most of the research and development in this area todate has been on realistic rendering, real-time animation, and“functional” autonomous behavior, while the issue of characterpersonality is typically left for an animator or script writer tofashion in an “artistic” (i.e., unprincipled) manner.

SUMMARY OF THE INVENTION

[0009] The present inventors have realized the need to utilizepersonality in efforts to develop better synthetic characters, and theneed for a method to apply personality to synthetic characters. Thepresent inventors have also realized that the application of certainpersonality traits to synthetic characters can make the syntheticcharacters more engaging, and more quickly accepted by users, easing thelearning and familiarization process of an application to which thesynthetic characters are applied.

[0010] Accordingly, it is an object of the present invention providedevelopers a workbench for developing and creating personalities forsynthetic characters.

[0011] It is another object of the present invention to provide aworkbench that allows personality traits to be programmed into asynthetic character developed for an application within a BASA-likearchitecture.

[0012] It is yet another object of the present invention to modify abehavioral hierarchy of a BASA architecture and provide for theselection of primary and non-conflicting secondary behaviorsimplementing personality traits of a character profile.

[0013] The present invention describes a system for designingrecognizable personalities in synthetic computer characters in order tobetter engage users. A personality design workbench enables designers todescribe personality attributes that modify a behavioral hierarchy,particularly useful for characters created in a simulation environmenthaving a reactive action selection architecture. These systems may beutilized to build applications for conversational characters(anthropomorphic user interfaces) and for entertainment purposes.

[0014] Typically, known characters share the same behavioral sets anddisplay only minimal, if any, inter-character individuation. To broadenpersonality expression in such characters (individuation), thepersonality design workbench outputs a set of ‘personality effectors’able to modify a prescribed set of behaviors within a BASA behavioralhierarchy to clearly portray uniquely different character personalities.

[0015] These and other objects are accomplished by a system forrendering personalities for synthetic characters, including apersonality trait selection device that displays at least one selectablepersonality trait, and a personality builder that groups the selectedpersonality traits into a character profile.

[0016] The personality trait selection device may include traitindicators (graduated dials, for example), each trait indicatorrepresenting an amount of a corresponding one of the selectablepersonality traits. The personality builder weights each selectedpersonality trait in said character profile according the amount of eachselected personality trait represented in the corresponding traitindicator.

[0017] The system may also include a personality attribute selectiondevice that displays at least one selectable personality attribute, anda mapper configured to map each selected personality attribute intoamounts of the trait indicators according to an amount each selectedpersonality attribute is represented in the selectable personalitytraits.

[0018] The invention includes a method of selecting behavior for asynthetic character, comprising the steps of computing a primaryactivation level of primary behaviors in each of plural nodes at a givenlevel of a modified behavior hierarchy, selecting a node having ahighest activation level, and executing the primary behavior inaccordance with an action defined by the selected node. The method mayinclude selecting a secondary behavior level, and discarding thesecondary behavior if it conflicts with a selected primary behavior.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] A more complete appreciation of the invention and many of theattendant advantages thereof will be readily obtained as the samebecomes better understood by reference to the following detaileddescription when considered in connection with the accompanyingdrawings, wherein:

[0020]FIG. 1 is an overview of a process for utilizing a workbench fordeveloping a personality to be applied to one or more syntheticcharacters;

[0021]FIG. 2 is an example of a behavioral hierarchy useful for aconversational character;

[0022]FIG. 3 is a diagram illustrating influences on a behavior fordetermination of a behavior activation level;

[0023]FIG. 4 is a classification hierarchy of personality effectors forimplementing character traits; and

[0024]FIG. 5 is a block diagram of one embodiment of a device forrendering a personality.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The present inventors have realized that a consistent,readily-identifiable personality is crucially important in syntheticcharacter applications for at least the following reasons:

[0026] Personality helps to engage the user. Both anthropomorphicinterfaces and entertainment applications require that the user “suspenddisbelief” while using them. A character with a well-designedpersonality can not only attract users into using a system but can helpmaintain the illusion that they are interacting with a real entity.

[0027] Personality facilitates user identification with the character in“ally” interfaces. In Conversational Character systems in which thecharacter acts as the user's ally in using a complex system, a properlydesigned personality can increase the user's sense of allegiance withthe character.

[0028] Personality can be used to establish the user's expectationsabout the system. A character with a dominant personality will beexpected to lead the user in mixed-initiative interactions; a submissivecharacter will be expected to do the opposite.

[0029] Personality can be used to control the user's style ofinteraction with the system. An immature or child-like character can beused to subconsciously coax the user into speaking slowly to accommodateimperfections in the speech recognition system.

[0030] Personality can be used to control the user's affective responseto the system. People have affinity for others who have personalitiessimilar to theirs and even greater affinity for those who modify theirpersonality to be more like them. Such phenomena could be leveraged tomake users like a particular product more than they would otherwise.

[0031] Personality is central for entertainment applications.Personality is central to character development which is crucial to anystory upon which an entertainment system may be based.

[0032] The present inventors have realized that personality may beutilized as an additional tool to develop better syntheticconversational characters and consequently better software applications.At a minimum, conversational characters provide a more familiar mode ofcommunication for users

enabling the character to have a more congenial relationship such as amentor or assistant to the user. The capacity to augment thesecharacters with identifiable personalities can produce not only richerapplications but also considerable design enhancements for thedeveloper.

[0033] Users will find personable synthetic characters to be moreengaging, more comfortable and ultimately easier with which to work. Thebenefits for fielded applications are clearly evident: ease of learningand tool familiarization, more ready acceptance by users and anapplication that is more highly regarded. From a design perspective,developers can more readily tailor multiple versions of an applicationfor different classes of user and experiment with different aspects ofpersonality to improve engagement with or enhance user acceptance of newapplications.

[0034] The present inventors have developed a novel approach to modelingpersonality. The model is the basis for a personality design workbenchthat assists developers in creating personable characters and alsounderlies a personality engine that realizes design specificationswithin character behavior. The design process, workbench and characterrealization are schematically depicted in FIG. 1.

[0035] The personality design workbench (personality workbench, orsimply workbench) outputs characters which are constructed to be usedwithin a specific reactive action selection architecture designed forautonomous synthetic character applications (BASA architectures, forexample). The personality workbench may also output characters for other(or multiple) architectures. The specific reactive action selectionarchitecture is ethological in origin and models how characters choosetheir behaviors based on constructs such as internal and externalstates, releasing mechanisms, inhibition and fatigue. Behavior selectionat each cycle in the system is determined by the outcome of a summativerelationship between these factors in a ‘winner take’ all competitionthat ensures that the character maintains coherency in its behavior.

[0036] The two problems addressed by the personality design workbenchare:

[0037] 1) how should personality be specified by a character designer;and

[0038] 2) how to map from the desired personality specifications to theselection of character behaviors such that those behaviors will clearlyreflect the intended personality.

[0039] The present invention presents a method for formalizingpersonality expression by drawing on research from two disciplines:personality trait theory and human communication theory. Trait theorysuggests that people clearly communicate notions of personality withdescriptive, trait-like words found in their cultural lexicon. Thesepersonality-based linguistic constructs or ‘labels’ are used by peopleto both describe and classify people based on behavioral similarities.Research has clearly demonstrated that traits are highly stablepredictors of future behavior, that people use only the featuresassociated with a small set of traits when classifying individualpersonalities and there is a high degree of consensus about the typicalbehavioral descriptors associated with specific traits. For example,most people describe introverts as being quiet, shy and retiring. It isclear, however, that the descriptors ‘quiet, shy and retiring’ do notprovide sufficient data upon which to create an introverted character.

[0040] In human communication theory, personality is seen as part of adynamic, communicative process—it is both emitted (or encoded) by anindividual and subsequently ‘decoded’ by a viewer. As encoders, humansdisplay aspects of their personality across multiple independentchannels which tend to be predominantly nonverbal in nature (e.g.,posture, gross body movement, facial and eye expression, or handgestures). Likewise, as decoders humans read from and combineinformation across multiple channels to form an overall impression ofboth the person and their message. Thus, research has shown thatintroverts tend to display the following kinds of behavior: they speaklittle and only when spoken to, they assume a closed body posture andthey tend to avoid eye contact. If a person (or an embodied character)were to display these behaviors they would be labeled as introverts. Ourmethodological approach is thus to isolate a basic set of personalitytraits and trait indicative nonverbal and verbal behaviors (i.e. peoplebelieve the behavior reflects a specific trait), and, finally translatethose behaviors into classes of ‘personality effectors’ that canmodulate a character's behavioral expression within the simulationenvironment so as to reflect the desired set of traits.

[0041] There have been a number of research projects examiningpersonality from two perspectives: the effects of personality onnon-anthropomorphic interface design (User Interface Design) and theimpact of personality on agent behavior in interactive, fictional worlds(Interactive Worlds).

[0042] User Interface Design

[0043] IBM's software agent WarpGuide is an agent-oriented task guidethat assists people with system tasks. It employs a personality(intelligent, friendly and unobtrusive) that was deemed task-appropriate(i.e. a mentor), a weak physical rendering of that personality (i.e.text boxes with rounded corners, warm colors) and a message content thatwas biased along the same personality dimensions. Experimental studiessuggested users responded positively to the characterization. However,since the actual interface was limited to text, these “agents” did notaddress the use of multiple simultaneous channels for conveyingpersonality (including, in particular, human trait-indicative non-verbalbehaviors).

[0044] Interactive Worlds

[0045] In The Virtual Theater project at Stanford, use asocial-psychological model of personality. However, it has manydeficiencies: 1) it is only able to select one behavior per time step(simultaneous use of multiple channels is not possible); 2) the basicaction selection approach is severely impoverished (no perception, nocoherence of action, and boredom/fatigue is modeled by randomization);3) no provision integrating more complex, deliberative behavior (e.g.,task planning, face-to-face communicative behavior); 4) use of traitsand non-verbal behaviors is ad-hoc; and 5) personality models aredifficult and confusing to author, and difficult to predict given thattraits can change over time.

[0046] Both the OZ project at CMU and the Affective Reasoner project atDePaul use a cognitive model of emotion based on Ortony. The emotionmodule in OZ reasons over recent events and the agent's goals to createan emotional interpretation of the current status of the system.Emotions are generated by comparing an event outcome to an agent'scurrent goals (e.g., goals succeed/fail which result in happy/sademotional states). The emotional interpretation (if any) is returned tothe behavior engine for use in selecting the agent's nextbehavior—allowing emotion to play a role in behavior selection. Elliot'sAffective Reasoner uses the same emotion model as OZ but gives agents arudimentary personality using two related constructs: disposition andtemperament. Disposition is an ‘interpretive’ personality construct thatenables agents to differentially interpret events. Temperament is the‘manifestive’ component of personality that guides an agent's expressionof emotional state in its behavior. Neither of these approaches utilizea trait-based specification of personality nor trait-indicativenon-verbal behaviors. The Oz project utilized very primitive syntheticcharacters which could only exhibit one behavior at a time (multiplesimultaneous channels are not available); the Affective Reasoner is atext-only system.

[0047] The present invention has the following features: 1) An approachbased on extensions to an ethologically-correct action selectionarchitecture; 2) the personality “workbench” provides multiple simpleauthoring mechanism; 3) all information about personality and itsbehavioral effects are encapsulated with a character; 4) a character canportray persistent trait-indicative non-verbal behaviors through“persistent personality effectors”; 5) a character can portrayconditional and temporally-bounded trait-indicative non-verbal behaviorsthrough “episodic personality effectors”; 6) a character can portraytrait-indicative actions in response to user actions through “reactivepersonality effectors”; 7) a character can modulate how it performsactions via “modulating personality effectors”; 8) a character can alterits perception and assessment (construal) of situations in itsenvironment through “construal personality effectors”; 9) the workbenchwill suggest non-behavioral modifications to the physical design of thecharacter; 10) characters can use multiple simultaneous communicationchannels to project personality; 11) the selection of traits andnon-verbal behaviors used are based on research in psychology andcommunications; and 12) personality is presented as indigenous to acharacter.

[0048] 1. The approach is based on extensions to anethologically-correct action selection architecture.

[0049] The “personality workbench” produces extensions and modificationsto a basic action selection architecture. This architecture ensuresnatural, coherent behavior while allowing for multiple, simultaneousactions, based on the character's perception of its environment,internal state and level of boredom and fatigue. This model can bereadily extended to perform deliberative actions such as task planning.

[0050] 2. The personality “workbench” provides multiple simple authoringmechanism.

[0051] Character designers can specify personality either by directmanipulation of trait values (e.g., a value between −10 and +10 on thewarm/cold dimension), through the selection of desired trait attributes(e.g., a character which is kind, sympathetic, soft-hearted andaffectionate), or via selection of desired non-verbal behaviors (e.g.,makes frequent and expansive gestures). Limited editions, combinations,and variations of the above mechanisms are also envisioned.

[0052] 3. All information about personality and its behavioral effectsis encapsulated within a character.

[0053] Trait-indicative nonverbal signaling behaviors and mechanisms forpersonality-biased modulation of behavior are organized in a set ofmodular data structures. These data structures, called “personalityeffectors”, enable multi-faceted personality expression which isenduring, consistent and predictable across time and events.

[0054] 4. A character can portray persistent trait-indicative non-verbalbehaviors through “persistent personality effectors”

[0055] Personality descriptions are used to select non-verbal behaviorsthat act as “default” behaviors for the character. They are subtle, havea high frequency of occurrence and will always be expressed wheneverthey do not conflict with the primary behavior the character isexecuting. Examples are body posture (e.g., slumped) and facialexpression (e.g., frown).

[0056] 5. A character can portray conditional and temporally-boundedtrait-indicative non-verbal behaviors through “episodic personalityeffectors”

[0057] Like persistent behaviors these are largely nonverbal in natureand unconscious. Unlike persistent behaviors they appear onlyperiodically, under well specified time constraints and are competitivewith other behaviors for activation. Examples are self-face touching asa signal of nervousness and gaze avoidance as a signal ofsubmissiveness.

[0058] 6. A character can portray trait-indicative actions in responseto user actions through “reactive personality effectors”.

[0059] For task-oriented application domains in which the character anduser have goals they are trying to achieve, the workbench will producebehaviors which enable the character to respond in a trait-indicativemanner to actions taken by the user. Examples are facial flush(submissive) or violence (dominant) when the user thwarts a goal of thecharacter.

[0060] 7. A character can modulate how it performs actions via“modulating personality effectors”.

[0061] Modulating personality effectors change how the characterperforms a given action. These are essentially hints to the variousbehavior routines which suggest, for example, that if the characterneeds to walk it should walk decisively (dominant) or nervously (tense).These effectors can also modify the performance of linguistic componentsof conversational characters by effecting word choice and sentencestructure decisions (e.g., “Could you possibly spare something todrink?” vs. “Give me some water!”). Modulating effectors can also besystemic in that they effect how the action selection architectureitself functions by modifying the amount of deliberation performed bythe system, the boredom and fatigue decay rates, etc.

[0062] 8. A character can alter its perception and assessment(construal) of situations in its environment through “construalpersonality effectors”.

[0063] Different personality types see the world differently. Forexample, tense character will react more rapidly to an approaching userthan a relaxed one will.

[0064] 9. The workbench will suggest non-behavioral modifications to thephysical design of the character.

[0065] These suggestions include both invariant physical features (bodytype, facial structure), variable personal artifacts, and suggestionsfor designing the character's setting (furniture, etc.).

[0066] 10. Characters can use multiple simultaneous communicationchannels to project personality.

[0067] Nonverbal behaviors appear in multiple, readily identifiablechannels (i.e. face, posture, etc.), they can be expressed in parallel(appear in two or more channels simultaneously) and often carryredundant messages. Having multiple concurrent communication channelsthrough the use of secondary behaviors will affect character-to-humancommunication in several fundamental ways:

[0068] Additional information channels broaden the communicationbandwidth and thus increases the amount of information being conveyed atany one point.

[0069] Cross channel message redundancy or the tendency for more thanone channel to carry the same message increases the probability that acharacter will be compatible with a wider range of users. For example,men tend to look more closely at hand gestures while women track eyebehavior and facial expression. Concurrent channels that carry the samemessage will reach a broader audience.

[0070] Characters who express personality using trait-indicativenonverbal behaviors closely mimic how humans tend to encode their owncommunicative messages and to decode the messages of others. Thisincreased compatibility (or match) between a character and an end-userwill have a number of benefits:

[0071] An increase in the engagement level of an end-user resulting inshorter learning curves.

[0072] Increased trust or confidence in a character's ability to assistan end-user (i.e. end-users come to see the character as an ‘ally’rather than a part of the complex system with which they are working).

[0073] End users will value the technology more highly (Reeves andNass).

[0074] 11. The selection of traits and non-verbal behaviors used arebased on research in psychology and communications.

[0075] The traits, trait attributes, and associated verbal andnon-verbal behaviors used in the personality workbench are all based onpsychology and human communication research.

[0076] 12. Personality is assumed to be indigenous to a character.

[0077] The present invention presents a personality wholly integratedacross all aspects of character realization including subsystems forappraisal, reactive behavior selection, persistent and episodic behaviorselection and modulation. All subsystems act in accordance to present apervasive, robust and consistent personality that remains intact overtime.

[0078] The personality of a character is created in a design phase andleaves the workbench with a set of fully integrated personalityattributes. This is unlike other approaches which have expressedcharacter personality in an ad-hoc and piecemeal fashion. Characterbehaviors in other systems are isolated and appear without coordinationin nonparallel behavioral subsystems. In short, personality expressionin the other approaches is non-systemic and results in characters thatappear shallow and unconvincing.

[0079] Technical Details

[0080] The “personality workbench” produces extensions and modificationsto the basic action selection architecture. The architecture uses anethological approach that ties behavior selection to traditionalanimal-world constructs, and may be extended to modeling humandeliberative behavior.

[0081] The behaviors within a BASA are arranged in a hierarchy, as shownin FIG. 2. Behaviors are activities which the character can perform,with those at the top of the hierarchy being more abstract categories ofbehavior and those at the bottom being operational in that they havesimulation routines associated with them which allow the character toperform them when commanded. Behaviors at each level in the hierarchycompete every time step of the simulation for control of the character.The result of this competition is one primary behavior, which is theprimary action the character is performing, and secondary behaviors. Thesecondary behaviors are executed as long as they do not conflict withthe primary behavior (where ‘conflict’ is defined with respect to thecharacter simulation controls). Thus, the architecture supports thesimulation of multiple parallel activities while maintaining a notion ofbehavioral focus.

[0082] Behaviors from each level are selected based on a computation ofactivation level and competition with sibling behaviors. The factorswhich go into the calculation of activity level are (see FIG. 3):

[0083] Endogenous variables. These correspond to internal states such asblood sugar level, hormone levels, hunger or thirst. Modeled as acontinuous variable where a sufficiently high value helps influence theselection of a behavior (drinking in response to thirst).

[0084] External states and releasing mechanisms. External states areevents or objects detected in the environment by sensors. Releasingmechanisms are ‘perceptual interpretations’ of external stimuli thatsignal an object or event is important to the agent.

[0085] Inhibition and fatigue (level of interest). When behaviorscompete amongst each other they do so on the basis of each behavior'sactivation level and inter-behavior inhibition. The activation value isdetermined in part by the endogenous variables and releasing mechanismsdescribed previously. These two factors cannot determine the rightamount of persistence (i.e. too much dithering between multiplebehaviors) nor account for opportunistic responses (i.e. not persistingin one behavior to the exclusion of other goals). To model persistence,competing behaviors are assumed to be mutually inhibiting—some behaviorscan post a higher gain for performance relative to others. The higherthe gain, the greater the persistence. Modeling opportunistic behaviorsrequires some notion of time-sharing among activities. The construct offatigue assumes that when a behavior is selected as primary, its levelof fatigue will increase proportionally over time, which will reduce theoverall activation value of that behavior. When the value of the currentprimary behavior falls below that of a competing behavior the competingbehavior will become primary.

[0086] This architecture can be further extended to simulate elements ofhuman deliberative behavior. In one embodiment, such extension isperformed by coupling the architecture with a task planner. When a planhas been produced, it can be used to bias the activation level for thebehavior(s) corresponding to the next step(s) in the plan when theirpreconditions are satisfied. In this way, the reactive action selectionarchitecture can be used as an intelligent plan execution environment,in which unplanned behaviors can still be performed opportunistically ifwarranted.

[0087] We summarize the features of a reactive behavior selectionarchitecture that are particularly amenable to expressing an integratedpersonality through trait-indicative behavior selection.

[0088] Behaviors are organized in loose hierarchies with the leaf nodesin the hierarchy containing character simulation information (i.e. thedirections about how to move the ‘muscles’ of the character to performthe behavior).

[0089] Character simulation information is described in terms ofspecific ‘degrees of freedom’ which refer to the points on thecharacter's body that can be moved. (These are a fixed set of points andgenerally correspond to the joints of the character's body.) Having acharacter make an expansive beckoning gesture with its arm requires theuse of three degrees of freedom—the elbow, wrist and shoulder.

[0090] At any point in time a character will be engaged in only oneactivity called a primary behavior. The primary behavior has uncontestedaccess to those degrees of freedom that it needs to perform.

[0091] One or more behaviors (called secondary behaviors) can executesimultaneously with the currently selected behavior if the following aretrue:

[0092] 1. The value of the secondary behavior is sufficiently high.

[0093] 2. The degrees of freedom necessary to perform the secondarybehavior are currently available (i.e. not being used).

[0094] Personality Design

[0095] Characters emerging from the personality design workbench havetrait profiles that will generate individuated characters. In a primaryembodiment, character trait profiles are made up of a set of fivebi-polar traits each of which varies along a continuous dimension. Thefive primary traits are the standard “Big Five” traits used most inpersonality theory research (see Table 1). TABLE 1 Trait Indices Used inPersonality Workbench Primary Traits Dominant/Submissive Warm/ColdConscientiousness Emotional Stability Openness

[0096] The workbench allows designers to create personality profiles fora character in three different ways. For example, in one embodiment:

[0097] 1. For each of the traits, the designer can position a graduateddial at an arbitrary point between two anchors (i.e. a highly warmcharacter would have the dial set very near the ‘warm’ anchor point onthe dial). Designers must set at least two of the primary personalitytraits for each character. Primary traits not set by the designer arearbitrarily given default neutral settings that point in the middle ofthe anchors. A trait with a neutral setting means that the trait wouldnot be readily inferred from the character's behavior (i.e. behaviorsindicative of neutral-rated traits can appear in a character's behaviorbut not with a frequency that would be recognized by users.)

[0098] 2. The designer can select personality attributes they want theircharacter to manifest. Personality attributes are linguistic labelswhich describe attributes typically associated with each trait anchorend-point (e.g., ‘warm’ attributes include kind, sympathetic,soft-hearted, affectionate). The Personality Workbench will then mapthese selected attributes into a trait profile which can then be editedusing method 1 above.

[0099] 3. The designer can select a set of trait-indicative behaviorsthat she wants the character to perform. For example, a designer may notknow what she wants in terms of a trait profile or attributes, but knowsthat she wants character which performs gesturing behaviors that areexpansive and highly frequent. The Personality Workbench will then mapthese selected behaviors into a trait profile which can then be editedusing method 1 above.

[0100] Personality Effectors

[0101] The Personality Workbench translates the trait profiles for acharacter into the following personality effectors which modify thebehavior of the basic action selection architecture described above (forexample, any method that would convey behaviors associated with thecharacter). A classification hierarchy of the personality effectors isillustrated in FIG. 4.

[0102] Persistent personality effectors. These are new behaviors addedto the hierarchy for the character being designed. Persistent nonverbalbehaviors have a constant activation value (i.e. are always ‘on’), arenot subject to decay (or fatigue) over time, and can never be selectedas primary behaviors (i.e., can only be used as secondary behaviors).They function as default behaviors as they will always be expressed ifthe necessary simulation controls for expression are available (i.e. notcurrently being used by the primary behavior). Thus, persistentbehaviors are constantly opportunistic—if the conditions are favorablethey will always execute. For example, an introverted character mayalways exhibit a slumped posture unless it needs to reach something.

[0103] Episodic personality effectors. These are new behaviors added tothe hierarchy for the character being designed. These behaviors aresimilar to persistent behaviors in that they represent trait-indicativenonverbal behaviors and can never be selected as primary behaviors (theyrepresent ‘unconscious’ non-deliberative actions on the part of thecharacter). However they act like other behaviors in the behavioralhierarchy in that their activation values can fluctuate in response toenvironmental stimuli (unlike persistent behaviors). For example,introverts tend to display gaze avoidance behavior, but displaying thatbehavior only makes sense in the presence of others.

[0104] Reactive personality effectors. These are new behaviors added tothe hierarchy for the character being designed. These behaviors aredomain-dependent, full-fledged additions to the behavior hierarchy for agiven application (i.e., they can have endogenous influences, releasingmechanisms, and level-of-interest functions), and represent the set ofpersonality-specific, deliberative actions that a character may take inresponse to a given situation. For example, a dominant character mayrespond with a violent behavior in response to a goal-obstruction,whereas an introverted character may only blush.

[0105] Modulating personality effectors. These act as hints to theaction selection system, affecting how different functions are performedrather than what functions are performed at any given time. There arethree kinds of modulating effectors: 1) behavioral, which effect how agiven behavioral simulation is executed (e.g., the ‘walk’ simulation maybe modified to perform ‘walk happily’, ‘walk timidly’, ‘walk boldly’, or‘walk sadly’); 2) linguistic, which effect how the language synthesisparts of a Conversational Character system function (i.e., effectingword choice and sentence structure); and 3) systemic, which impacts theoverall action selection system (e.g., trading deliberation vs. actionfor a conscientious character, increasing boredom/fatigue rates forhappy-go-lucky characters, etc.).

[0106] Construal or appraisal functions. Personality can modify acharacter's interpretation of world events. In an ethological model thiswould require modifications in the form of increased or decreased gainson existing releasing mechanisms or adding new releasing mechanisms toexisting behaviors. For example, a more submissive person would detect adominant person sooner and would react accordingly in their presence(i.e. displaying submissive behaviors). At a deeper, psycho-sociologicallevel, appraisal functions determine the character's assessment ofactions taken by others and its impact on the character's affectivestate (endogenous variables), and is driven, at least in part, by thecharacter's personality.

[0107] Non-behavioral effectors. Characters will have a physicalpresence for which viewers will infer personality characteristics. Thesefeatures are physical in nature and are apparent throughout the lifetimeof the character. Some examples include: body type (endomorph,ectomorph, mesomorph), facial structure (round/triangular face),attractiveness, and physical objects that the character may surrounditself with (furniture, art, etc.). The initial version the PersonalityWorkbench will simply popup a window with suggestions regardingappearance factors; future versions may actually be able to modify thecharacter's 3D design.

[0108]FIG. 5 is a block diagram of one possible implementation of adevice for rendering a personality. A behavior hierarchy is created ormodified by a modifier 510. The modifier may include a device such asthe personality workbench illustrated in FIG. 1.

[0109] The behavioral hierarchy 520 provides information on primary andsecondary behaviors, modulation, and construal personality effectors,which are each interpreted by appropriate decices (primary activationdevice 552, secondary activation device 554, modulator 540, andconstrual device 530, respectively). Each of these devices provideinputs (specific action or amount of movement in a gesture, for example)to the activation device regarding behaviors consistent with andeffecting the information in the behavioral hierarchy.

[0110] A construal device 530 receives external stimuli 500 and providesan interpretation of that stimuli to the activation device 550. Theactivation device 550 selects non-conflicting behaviors and considersexternal significance of external stimuli, and notifies a behaviorexecution module 560 of a selected behavior.

[0111] At this point, it is worthwhile to review some features of thepresent invention. The present invention allows a personality profilefrom a design phase (such as the output of the personality workbenchdescribed in FIG. 1) which is then translated into a new behaviorialheirarchy via a set of personality effectors. The new personality is anindividuated behavioral hierarchy produced with personality biasedbehaviors, including, primary and secondary behaviors, modulatedpre-existing behaviors, and construal changes. The new behavioralhierarchy is created at compile time (i.e., before the character isrunning), and has the capability to (1) add new behaviors (primary andsecondary), (2) modulate existing behaviors in an existing hierarchy,and (3) modify a character's perception of external events.

[0112] Then, at run time, personality expression is accomplished in thefollowing ways:

[0113] (1) Parallel use of secondary behaviors as a way of expressingdifferences between characters having a same primary behavior (thesecondary behaviors grabbing free DOFs for an available forinstantiating the secondary behavior);

[0114] (2) The use of new trait indicative primary behaviors, along withtheir own internal releasing mechanisms, that were added via thepersonality profile; and

[0115] (3) Modulation of existing behaviors in the hierarchy, and/orperceptual and interpretive changes according to the personalityprofile.

[0116] The present invention as discussed herein has been described inreference to rendering a personality and methods and devices utilized inrendering a personality, preferably for synthetic characters. However,the teachings of the present invention may be applied to numerous otherendeavors, including equipment for suggesting behaviors for humans,actors, electronic equipment, voice boxes, announcement devices, orother devices not necessarily associated with a synthetic character. Inaddition, the teachings of the present invention apply to any type ofanimated interface or presentation device (virtual classroom instructor,or tutor, for example) or other animated devices or icons. The presentinvention may be utilized in a computer interface or for directingoperations of any type of equipment of varying configurations(televisions, VCR's, stereos, radar devices, toys, mechanical equipmentsuch as heavy machinery, and building management/maintenance devices asjust a few examples).

[0117] The present invention may be conveniently implemented using aconventional general purpose or a specialized digital computer ormicroprocessor programmed according to the teachings of the presentdisclosure, as will be apparent to those skilled in the computer art.

[0118] Appropriate software coding can readily be prepared by skilledprogrammers based on the teachings of the present disclosure, as will beapparent to those skilled in the software art. The invention may also beimplemented by the preparation of application specific integratedcircuits or by interconnecting an appropriate network of conventionalcomponent circuits, as will be readily apparent to those skilled in theart.

[0119] The present invention includes a computer program product whichis a storage medium (media) having instructions stored thereon/in whichcan be used to program a computer to perform any of the processes andmethods of the present invention. The storage medium can include, but isnot limited to, any type of disk including floppy disks, optical discs,DVD, CD-ROMs, microdrive, and magneto-optical disks, ROMs, RAMs, EPROMS,EEPROMS, DRAMs, VRAMS, flash memory devices, magnetic or optical cards,nanosystems (including molecular memory ICs), or any type of media ordevice suitable for storing instructions and/or data.

[0120] Stored on any one of the computer readable medium (media), thepresent invention includes software for controlling both the hardware ofthe general purpose/specialized computer or microprocessor, and forenabling the computer or microprocessor to interact with a human user orother mechanism utilizing the processing of the present invention. Suchsoftware may include, but is not limited to, device drivers, peripheralequipment programs, operating systems, and user applications.Ultimately, such computer readable media further includes software forperforming the functions of the present invention as described above.

[0121] Included in the programming (software) of the general/specializedcomputer or microprocessor are software modules for implementing theteachings of the present invention, including, but not limited to, inputand identification of user inputs, selection of personality traits,building a character profile, computing activation levels, and selectionand activation of personality behaviors including movements and speechof a synthetic character or other animated character, voice, or display.

[0122] Obviously, numerous modifications and variations of the presentinvention are possible in light of the above teachings. It is thereforeto be understood that within the scope of the appended claims, theinvention may be practiced otherwise than as specifically describedherein.

What is claimed is:
 1. A system for designing personalities forsynthetic characters, comprising: a personality trait selection devicethat displays at least one selectable personality trait; and apersonality builder that groups the selected personality traits into acharacter profile.
 2. The system according to claim 1, wherein: saidpersonality trait selection device comprises at least one traitindicator, each trait indicator representing an amount of acorresponding one of the selectable personality traits; and saidpersonality builder weights each selected personality trait in saidcharacter profile according the amount of each selected personalitytrait represented in the corresponding trait indicator.
 3. The systemaccording to claim 2, wherein the trait indicators are graduated dialsoperating between a high anchor and a low anchor.
 4. The systemaccording to claim 2, further comprising: a personality attributeselection device that displays at least one selectable personalityattribute; and a mapper configured to map each selected personalityattribute into amounts of the trait indicators according to an amounteach selected personality attribute is represented in the selectablepersonality traits.
 5. The system according to claim 2, wherein theselectable personality traits include at least one primary trait ofdominance, warmth, conscientiousness, emotional stability, and openness.6. The system according to claim 2, further comprising: a traitindicative behavior selection device that displays at least oneselectable trait indicative behavior; and a mapper configured to mapeach selected trait indicative behavior into amounts of the traitindicators according to an amount each selected personality attribute isrepresented in the selectable personality traits.
 7. The systemaccording to claim 1, wherein said character profile comprises atranslation of the selected personality traits into a weighted set ofpersonality traits.
 8. The system according to claim 1, furthercomprising: a physical modification device configured to modify physicalcharacteristics of said synthetic character based on the characterprofile.
 9. A method of rendering a personality, comprising the step of:rendering at least one behavior of a synthetic character based on acharacter profile having selected personality traits.
 10. The methodaccording to claim 9, wherein said step of rendering includes the stepof: specifying at least one trait indicative behavior; and implementingbehaviors consistent with the trait indicative behaviors.
 11. The methodaccording to claim 10, wherein: said trait indicative behaviors includeat least one primary behavior; said step of specifying includes the stepof specifying a set of releasing mechanisms associated with thespecified primary behaviors; and said step of rendering includes thesteps of, interpreting stimuli external to said personality based onsaid set of releasing mechanisms, and rendering said at least onebehavior of the synthetic character based on the interpreted externalstimuli.
 12. The method according to claim 9, wherein said step ofrendering comprises the steps of: specifying at least one secondarybehavior; and implementing the secondary behaviors as one of persistentand episodic behaviors.
 13. The method according to claim 9, whereinsaid step of rendering comprises the step of: modulating an existingbehavior based on the character profile.
 14. The method according toclaim 9, wherein said step of rendering comprises the step of: modifyinga construal process utilized by the personality.
 15. The methodaccording to claim 14, wherein said construal process includes processesfor perception and assessment of situations in an environment of whichthe personality is located.
 16. A method of selecting behavior for asynthetic character, comprising the steps of: computing an primaryactivation level of primary behaviors in each of plural nodes at a givenlevel of a modified behavior hierarchy; selecting a node having ahighest activation level; and executing the primary behavior inaccordance with an action defined by the selected node.
 17. The methodaccording to claim 16, further comprising the steps of: computing ansecondary activation level for at least one trait indicative secondarybehavior in each of plural nodes at the given level of the behaviorhierarchy; disregarding secondary behaviors that conflict with theselected primary behavior; selecting secondary behaviors based on thesecondary behavior activation level computed; repeating said steps ofcomputing, disregarding, and selecting until no degrees of freedomunused by the primary and selected secondary behaviors sufficient toactivate any remaining secondary behaviors exist; and executing theselected secondary behaviors.
 18. The method according to claim 16,wherein: said step of computing comprises, determining values, includingat least one of a level of interest, a value of inhibitory links, avalue of releasing mechanisms, a level of fatigue, and a value ofendogenous variables associated with a behavior, for factors related towhether a behavior should be activated, and computing said primaryactivation level based on the values determined.
 19. The methodaccording to claim 18, further comprising the step of: increasing saidlevel of fatigue associated with a behavior based on a length of timesaid behavior has been activated.
 20. The method according to claim 19,further comprising the step of: biasing an activation level for plansteps based on a plan.